2 * ASPEED Static Memory Controller driver
4 * Copyright (c) 2015-2016, IBM Corporation.
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/bug.h>
13 #include <linux/device.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/mtd/mtd.h>
18 #include <linux/mtd/partitions.h>
19 #include <linux/mtd/spi-nor.h>
21 #include <linux/of_platform.h>
22 #include <linux/sysfs.h>
24 #define DEVICE_NAME "aspeed-smc"
27 * The driver only support SPI flash
29 enum aspeed_smc_flash_type {
35 struct aspeed_smc_chip;
37 struct aspeed_smc_info {
38 u32 maxsize; /* maximum size of chip window */
39 u8 nce; /* number of chip enables */
40 bool hastype; /* flash type field exists in config reg */
41 u8 we0; /* shift for write enable bit for CE0 */
42 u8 ctl0; /* offset in regs of ctl for CE0 */
44 void (*set_4b)(struct aspeed_smc_chip *chip);
47 static void aspeed_smc_chip_set_4b_spi_2400(struct aspeed_smc_chip *chip);
48 static void aspeed_smc_chip_set_4b(struct aspeed_smc_chip *chip);
50 static const struct aspeed_smc_info fmc_2400_info = {
51 .maxsize = 64 * 1024 * 1024,
56 .set_4b = aspeed_smc_chip_set_4b,
59 static const struct aspeed_smc_info spi_2400_info = {
60 .maxsize = 64 * 1024 * 1024,
65 .set_4b = aspeed_smc_chip_set_4b_spi_2400,
68 static const struct aspeed_smc_info fmc_2500_info = {
69 .maxsize = 256 * 1024 * 1024,
74 .set_4b = aspeed_smc_chip_set_4b,
77 static const struct aspeed_smc_info spi_2500_info = {
78 .maxsize = 128 * 1024 * 1024,
83 .set_4b = aspeed_smc_chip_set_4b,
86 enum aspeed_smc_ctl_reg_value {
87 smc_base, /* base value without mode for other commands */
88 smc_read, /* command reg for (maybe fast) reads */
89 smc_write, /* command reg for writes */
93 struct aspeed_smc_controller;
95 struct aspeed_smc_chip {
97 struct aspeed_smc_controller *controller;
98 void __iomem *ctl; /* control register */
99 void __iomem *ahb_base; /* base of chip window */
100 u32 ctl_val[smc_max]; /* control settings */
101 enum aspeed_smc_flash_type type; /* what type of flash */
105 struct aspeed_smc_controller {
108 struct mutex mutex; /* controller access mutex */
109 const struct aspeed_smc_info *info; /* type info of controller */
110 void __iomem *regs; /* controller registers */
111 void __iomem *ahb_base; /* per-chip windows resource */
113 struct aspeed_smc_chip *chips[0]; /* pointers to attached chips */
117 * SPI Flash Configuration Register (AST2500 SPI)
119 * Type setting Register (AST2500 FMC).
120 * CE0 and CE1 can only be of type SPI. CE2 can be of type NOR but the
121 * driver does not support it.
123 #define CONFIG_REG 0x0
124 #define CONFIG_DISABLE_LEGACY BIT(31) /* 1 */
126 #define CONFIG_CE2_WRITE BIT(18)
127 #define CONFIG_CE1_WRITE BIT(17)
128 #define CONFIG_CE0_WRITE BIT(16)
130 #define CONFIG_CE2_TYPE BIT(4) /* AST2500 FMC only */
131 #define CONFIG_CE1_TYPE BIT(2) /* AST2500 FMC only */
132 #define CONFIG_CE0_TYPE BIT(0) /* AST2500 FMC only */
135 * CE Control Register
137 #define CE_CONTROL_REG 0x4
140 * CEx Control Register
142 #define CONTROL_AAF_MODE BIT(31)
143 #define CONTROL_IO_MODE_MASK GENMASK(30, 28)
144 #define CONTROL_IO_DUAL_DATA BIT(29)
145 #define CONTROL_IO_DUAL_ADDR_DATA (BIT(29) | BIT(28))
146 #define CONTROL_IO_QUAD_DATA BIT(30)
147 #define CONTROL_IO_QUAD_ADDR_DATA (BIT(30) | BIT(28))
148 #define CONTROL_CE_INACTIVE_SHIFT 24
149 #define CONTROL_CE_INACTIVE_MASK GENMASK(27, \
150 CONTROL_CE_INACTIVE_SHIFT)
151 /* 0 = 16T ... 15 = 1T T=HCLK */
152 #define CONTROL_COMMAND_SHIFT 16
153 #define CONTROL_DUMMY_COMMAND_OUT BIT(15)
154 #define CONTROL_IO_DUMMY_HI BIT(14)
155 #define CONTROL_IO_DUMMY_HI_SHIFT 14
156 #define CONTROL_CLK_DIV4 BIT(13) /* others */
157 #define CONTROL_IO_ADDRESS_4B BIT(13) /* AST2400 SPI */
158 #define CONTROL_RW_MERGE BIT(12)
159 #define CONTROL_IO_DUMMY_LO_SHIFT 6
160 #define CONTROL_IO_DUMMY_LO GENMASK(7, \
161 CONTROL_IO_DUMMY_LO_SHIFT)
162 #define CONTROL_IO_DUMMY_MASK (CONTROL_IO_DUMMY_HI | \
164 #define CONTROL_IO_DUMMY_SET(dummy) \
165 (((((dummy) >> 2) & 0x1) << CONTROL_IO_DUMMY_HI_SHIFT) | \
166 (((dummy) & 0x3) << CONTROL_IO_DUMMY_LO_SHIFT))
168 #define CONTROL_CLOCK_FREQ_SEL_SHIFT 8
169 #define CONTROL_CLOCK_FREQ_SEL_MASK GENMASK(11, \
170 CONTROL_CLOCK_FREQ_SEL_SHIFT)
171 #define CONTROL_LSB_FIRST BIT(5)
172 #define CONTROL_CLOCK_MODE_3 BIT(4)
173 #define CONTROL_IN_DUAL_DATA BIT(3)
174 #define CONTROL_CE_STOP_ACTIVE_CONTROL BIT(2)
175 #define CONTROL_COMMAND_MODE_MASK GENMASK(1, 0)
176 #define CONTROL_COMMAND_MODE_NORMAL 0
177 #define CONTROL_COMMAND_MODE_FREAD 1
178 #define CONTROL_COMMAND_MODE_WRITE 2
179 #define CONTROL_COMMAND_MODE_USER 3
181 #define CONTROL_KEEP_MASK \
182 (CONTROL_AAF_MODE | CONTROL_CE_INACTIVE_MASK | CONTROL_CLK_DIV4 | \
183 CONTROL_IO_DUMMY_MASK | CONTROL_CLOCK_FREQ_SEL_MASK | \
184 CONTROL_LSB_FIRST | CONTROL_CLOCK_MODE_3)
187 * The Segment Register uses a 8MB unit to encode the start address
188 * and the end address of the mapping window of a flash SPI slave :
190 * | byte 1 | byte 2 | byte 3 | byte 4 |
191 * +--------+--------+--------+--------+
192 * | end | start | 0 | 0 |
194 #define SEGMENT_ADDR_REG0 0x30
195 #define SEGMENT_ADDR_START(_r) ((((_r) >> 16) & 0xFF) << 23)
196 #define SEGMENT_ADDR_END(_r) ((((_r) >> 24) & 0xFF) << 23)
199 * In user mode all data bytes read or written to the chip decode address
200 * range are transferred to or from the SPI bus. The range is treated as a
201 * fifo of arbitratry 1, 2, or 4 byte width but each write has to be aligned
202 * to its size. The address within the multiple 8kB range is ignored when
203 * sending bytes to the SPI bus.
205 * On the arm architecture, as of Linux version 4.3, memcpy_fromio and
206 * memcpy_toio on little endian targets use the optimized memcpy routines
207 * that were designed for well behavied memory storage. These routines
208 * have a stutter if the source and destination are not both word aligned,
209 * once with a duplicate access to the source after aligning to the
210 * destination to a word boundary, and again with a duplicate access to
211 * the source when the final byte count is not word aligned.
213 * When writing or reading the fifo this stutter discards data or sends
214 * too much data to the fifo and can not be used by this driver.
216 * While the low level io string routines that implement the insl family do
217 * the desired accesses and memory increments, the cross architecture io
218 * macros make them essentially impossible to use on a memory mapped address
219 * instead of a a token from the call to iomap of an io port.
221 * These fifo routines use readl and friends to a constant io port and update
222 * the memory buffer pointer and count via explicit code. The final updates
223 * to len are optimistically suppressed.
225 static int aspeed_smc_read_from_ahb(void *buf, void __iomem *src, size_t len)
229 if (IS_ALIGNED((uintptr_t)src, sizeof(uintptr_t)) &&
230 IS_ALIGNED((uintptr_t)buf, sizeof(uintptr_t))) {
231 ioread32_rep(src, buf, len >> 2);
235 ioread8_rep(src, (u8 *)buf + offset, len);
239 static int aspeed_smc_write_to_ahb(void __iomem *dst, const void *buf,
244 if (IS_ALIGNED((uintptr_t)dst, sizeof(uintptr_t)) &&
245 IS_ALIGNED((uintptr_t)buf, sizeof(uintptr_t))) {
246 iowrite32_rep(dst, buf, len >> 2);
250 iowrite8_rep(dst, (const u8 *)buf + offset, len);
254 static inline u32 aspeed_smc_chip_write_bit(struct aspeed_smc_chip *chip)
256 return BIT(chip->controller->info->we0 + chip->cs);
259 static void aspeed_smc_chip_check_config(struct aspeed_smc_chip *chip)
261 struct aspeed_smc_controller *controller = chip->controller;
264 reg = readl(controller->regs + CONFIG_REG);
266 if (reg & aspeed_smc_chip_write_bit(chip))
269 dev_dbg(controller->dev, "config write is not set ! @%p: 0x%08x\n",
270 controller->regs + CONFIG_REG, reg);
271 reg |= aspeed_smc_chip_write_bit(chip);
272 writel(reg, controller->regs + CONFIG_REG);
275 static void aspeed_smc_start_user(struct spi_nor *nor)
277 struct aspeed_smc_chip *chip = nor->priv;
278 u32 ctl = chip->ctl_val[smc_base];
281 * When the chip is controlled in user mode, we need write
282 * access to send the opcodes to it. So check the config.
284 aspeed_smc_chip_check_config(chip);
286 ctl |= CONTROL_COMMAND_MODE_USER |
287 CONTROL_CE_STOP_ACTIVE_CONTROL;
288 writel(ctl, chip->ctl);
290 ctl &= ~CONTROL_CE_STOP_ACTIVE_CONTROL;
291 writel(ctl, chip->ctl);
294 static void aspeed_smc_stop_user(struct spi_nor *nor)
296 struct aspeed_smc_chip *chip = nor->priv;
298 u32 ctl = chip->ctl_val[smc_read];
299 u32 ctl2 = ctl | CONTROL_COMMAND_MODE_USER |
300 CONTROL_CE_STOP_ACTIVE_CONTROL;
302 writel(ctl2, chip->ctl); /* stop user CE control */
303 writel(ctl, chip->ctl); /* default to fread or read mode */
306 static int aspeed_smc_prep(struct spi_nor *nor, enum spi_nor_ops ops)
308 struct aspeed_smc_chip *chip = nor->priv;
310 mutex_lock(&chip->controller->mutex);
314 static void aspeed_smc_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
316 struct aspeed_smc_chip *chip = nor->priv;
318 mutex_unlock(&chip->controller->mutex);
321 static int aspeed_smc_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
323 struct aspeed_smc_chip *chip = nor->priv;
325 aspeed_smc_start_user(nor);
326 aspeed_smc_write_to_ahb(chip->ahb_base, &opcode, 1);
327 aspeed_smc_read_from_ahb(buf, chip->ahb_base, len);
328 aspeed_smc_stop_user(nor);
332 static int aspeed_smc_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
335 struct aspeed_smc_chip *chip = nor->priv;
337 aspeed_smc_start_user(nor);
338 aspeed_smc_write_to_ahb(chip->ahb_base, &opcode, 1);
339 aspeed_smc_write_to_ahb(chip->ahb_base, buf, len);
340 aspeed_smc_stop_user(nor);
344 static void aspeed_smc_send_cmd_addr(struct spi_nor *nor, u8 cmd, u32 addr)
346 struct aspeed_smc_chip *chip = nor->priv;
350 switch (nor->addr_width) {
352 WARN_ONCE(1, "Unexpected address width %u, defaulting to 3\n",
356 cmdaddr = addr & 0xFFFFFF;
357 cmdaddr |= cmd << 24;
359 temp = cpu_to_be32(cmdaddr);
360 aspeed_smc_write_to_ahb(chip->ahb_base, &temp, 4);
363 temp = cpu_to_be32(addr);
364 aspeed_smc_write_to_ahb(chip->ahb_base, &cmd, 1);
365 aspeed_smc_write_to_ahb(chip->ahb_base, &temp, 4);
370 static ssize_t aspeed_smc_read_user(struct spi_nor *nor, loff_t from,
371 size_t len, u_char *read_buf)
373 struct aspeed_smc_chip *chip = nor->priv;
377 aspeed_smc_start_user(nor);
378 aspeed_smc_send_cmd_addr(nor, nor->read_opcode, from);
379 for (i = 0; i < chip->nor.read_dummy / 8; i++)
380 aspeed_smc_write_to_ahb(chip->ahb_base, &dummy, sizeof(dummy));
382 aspeed_smc_read_from_ahb(read_buf, chip->ahb_base, len);
383 aspeed_smc_stop_user(nor);
387 static ssize_t aspeed_smc_write_user(struct spi_nor *nor, loff_t to,
388 size_t len, const u_char *write_buf)
390 struct aspeed_smc_chip *chip = nor->priv;
392 aspeed_smc_start_user(nor);
393 aspeed_smc_send_cmd_addr(nor, nor->program_opcode, to);
394 aspeed_smc_write_to_ahb(chip->ahb_base, write_buf, len);
395 aspeed_smc_stop_user(nor);
399 static int aspeed_smc_unregister(struct aspeed_smc_controller *controller)
401 struct aspeed_smc_chip *chip;
404 for (n = 0; n < controller->info->nce; n++) {
405 chip = controller->chips[n];
407 mtd_device_unregister(&chip->nor.mtd);
413 static int aspeed_smc_remove(struct platform_device *dev)
415 return aspeed_smc_unregister(platform_get_drvdata(dev));
418 static const struct of_device_id aspeed_smc_matches[] = {
419 { .compatible = "aspeed,ast2400-fmc", .data = &fmc_2400_info },
420 { .compatible = "aspeed,ast2400-spi", .data = &spi_2400_info },
421 { .compatible = "aspeed,ast2500-fmc", .data = &fmc_2500_info },
422 { .compatible = "aspeed,ast2500-spi", .data = &spi_2500_info },
425 MODULE_DEVICE_TABLE(of, aspeed_smc_matches);
428 * Each chip has a mapping window defined by a segment address
429 * register defining a start and an end address on the AHB bus. These
430 * addresses can be configured to fit the chip size and offer a
431 * contiguous memory region across chips. For the moment, we only
432 * check that each chip segment is valid.
434 static void __iomem *aspeed_smc_chip_base(struct aspeed_smc_chip *chip,
435 struct resource *res)
437 struct aspeed_smc_controller *controller = chip->controller;
441 if (controller->info->nce > 1) {
442 reg = readl(controller->regs + SEGMENT_ADDR_REG0 +
445 if (SEGMENT_ADDR_START(reg) >= SEGMENT_ADDR_END(reg))
448 offset = SEGMENT_ADDR_START(reg) - res->start;
451 return controller->ahb_base + offset;
454 static void aspeed_smc_chip_enable_write(struct aspeed_smc_chip *chip)
456 struct aspeed_smc_controller *controller = chip->controller;
459 reg = readl(controller->regs + CONFIG_REG);
461 reg |= aspeed_smc_chip_write_bit(chip);
462 writel(reg, controller->regs + CONFIG_REG);
465 static void aspeed_smc_chip_set_type(struct aspeed_smc_chip *chip, int type)
467 struct aspeed_smc_controller *controller = chip->controller;
472 reg = readl(controller->regs + CONFIG_REG);
473 reg &= ~(3 << (chip->cs * 2));
474 reg |= chip->type << (chip->cs * 2);
475 writel(reg, controller->regs + CONFIG_REG);
479 * The AST2500 FMC flash controller should be strapped by hardware, or
480 * autodetected, but the AST2500 SPI flash needs to be set.
482 static void aspeed_smc_chip_set_4b(struct aspeed_smc_chip *chip)
484 struct aspeed_smc_controller *controller = chip->controller;
487 if (chip->controller->info == &spi_2500_info) {
488 reg = readl(controller->regs + CE_CONTROL_REG);
489 reg |= 1 << chip->cs;
490 writel(reg, controller->regs + CE_CONTROL_REG);
495 * The AST2400 SPI flash controller does not have a CE Control
496 * register. It uses the CE0 control register to set 4Byte mode at the
499 static void aspeed_smc_chip_set_4b_spi_2400(struct aspeed_smc_chip *chip)
501 chip->ctl_val[smc_base] |= CONTROL_IO_ADDRESS_4B;
502 chip->ctl_val[smc_read] |= CONTROL_IO_ADDRESS_4B;
505 static int aspeed_smc_chip_setup_init(struct aspeed_smc_chip *chip,
506 struct resource *res)
508 struct aspeed_smc_controller *controller = chip->controller;
509 const struct aspeed_smc_info *info = controller->info;
513 * Always turn on the write enable bit to allow opcodes to be
516 aspeed_smc_chip_enable_write(chip);
518 /* The driver only supports SPI type flash */
520 aspeed_smc_chip_set_type(chip, smc_type_spi);
523 * Configure chip base address in memory
525 chip->ahb_base = aspeed_smc_chip_base(chip, res);
526 if (!chip->ahb_base) {
527 dev_warn(chip->nor.dev, "CE segment window closed.\n");
532 * Get value of the inherited control register. U-Boot usually
533 * does some timing calibration on the FMC chip, so it's good
534 * to keep them. In the future, we should handle calibration
537 reg = readl(chip->ctl);
538 dev_dbg(controller->dev, "control register: %08x\n", reg);
540 base_reg = reg & CONTROL_KEEP_MASK;
541 if (base_reg != reg) {
542 dev_dbg(controller->dev,
543 "control register changed to: %08x\n",
546 chip->ctl_val[smc_base] = base_reg;
549 * Retain the prior value of the control register as the
550 * default if it was normal access mode. Otherwise start with
551 * the sanitized base value set to read mode.
553 if ((reg & CONTROL_COMMAND_MODE_MASK) ==
554 CONTROL_COMMAND_MODE_NORMAL)
555 chip->ctl_val[smc_read] = reg;
557 chip->ctl_val[smc_read] = chip->ctl_val[smc_base] |
558 CONTROL_COMMAND_MODE_NORMAL;
560 dev_dbg(controller->dev, "default control register: %08x\n",
561 chip->ctl_val[smc_read]);
565 static int aspeed_smc_chip_setup_finish(struct aspeed_smc_chip *chip)
567 struct aspeed_smc_controller *controller = chip->controller;
568 const struct aspeed_smc_info *info = controller->info;
571 if (chip->nor.addr_width == 4 && info->set_4b)
575 * base mode has not been optimized yet. use it for writes.
577 chip->ctl_val[smc_write] = chip->ctl_val[smc_base] |
578 chip->nor.program_opcode << CONTROL_COMMAND_SHIFT |
579 CONTROL_COMMAND_MODE_WRITE;
581 dev_dbg(controller->dev, "write control register: %08x\n",
582 chip->ctl_val[smc_write]);
585 * TODO: Adjust clocks if fast read is supported and interpret
586 * SPI-NOR flags to adjust controller settings.
588 switch (chip->nor.flash_read) {
590 cmd = CONTROL_COMMAND_MODE_NORMAL;
593 cmd = CONTROL_COMMAND_MODE_FREAD;
596 dev_err(chip->nor.dev, "unsupported SPI read mode\n");
600 chip->ctl_val[smc_read] |= cmd |
601 CONTROL_IO_DUMMY_SET(chip->nor.read_dummy / 8);
603 dev_dbg(controller->dev, "base control register: %08x\n",
604 chip->ctl_val[smc_read]);
608 static int aspeed_smc_setup_flash(struct aspeed_smc_controller *controller,
609 struct device_node *np, struct resource *r)
611 const struct aspeed_smc_info *info = controller->info;
612 struct device *dev = controller->dev;
613 struct device_node *child;
617 for_each_available_child_of_node(np, child) {
618 struct aspeed_smc_chip *chip;
620 struct mtd_info *mtd;
622 /* This driver does not support NAND or NOR flash devices. */
623 if (!of_device_is_compatible(child, "jedec,spi-nor"))
626 ret = of_property_read_u32(child, "reg", &cs);
628 dev_err(dev, "Couldn't not read chip select.\n");
632 if (cs >= info->nce) {
633 dev_err(dev, "Chip select %d out of range.\n",
639 if (controller->chips[cs]) {
640 dev_err(dev, "Chip select %d already in use by %s\n",
641 cs, dev_name(controller->chips[cs]->nor.dev));
646 chip = devm_kzalloc(controller->dev, sizeof(*chip), GFP_KERNEL);
652 chip->controller = controller;
653 chip->ctl = controller->regs + info->ctl0 + cs * 4;
661 spi_nor_set_flash_node(nor, child);
662 nor->read = aspeed_smc_read_user;
663 nor->write = aspeed_smc_write_user;
664 nor->read_reg = aspeed_smc_read_reg;
665 nor->write_reg = aspeed_smc_write_reg;
666 nor->prepare = aspeed_smc_prep;
667 nor->unprepare = aspeed_smc_unprep;
669 ret = aspeed_smc_chip_setup_init(chip, r);
674 * TODO: Add support for SPI_NOR_QUAD and SPI_NOR_DUAL
675 * attach when board support is present as determined
678 ret = spi_nor_scan(nor, NULL, SPI_NOR_NORMAL);
682 ret = aspeed_smc_chip_setup_finish(chip);
686 ret = mtd_device_register(mtd, NULL, 0);
690 controller->chips[cs] = chip;
694 aspeed_smc_unregister(controller);
699 static int aspeed_smc_probe(struct platform_device *pdev)
701 struct device_node *np = pdev->dev.of_node;
702 struct device *dev = &pdev->dev;
703 struct aspeed_smc_controller *controller;
704 const struct of_device_id *match;
705 const struct aspeed_smc_info *info;
706 struct resource *res;
709 match = of_match_device(aspeed_smc_matches, &pdev->dev);
710 if (!match || !match->data)
714 controller = devm_kzalloc(&pdev->dev, sizeof(*controller) +
715 info->nce * sizeof(controller->chips[0]), GFP_KERNEL);
718 controller->info = info;
719 controller->dev = dev;
721 mutex_init(&controller->mutex);
722 platform_set_drvdata(pdev, controller);
724 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
725 controller->regs = devm_ioremap_resource(dev, res);
726 if (IS_ERR(controller->regs))
727 return PTR_ERR(controller->regs);
729 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
730 controller->ahb_base = devm_ioremap_resource(dev, res);
731 if (IS_ERR(controller->ahb_base))
732 return PTR_ERR(controller->ahb_base);
734 ret = aspeed_smc_setup_flash(controller, np, res);
736 dev_err(dev, "Aspeed SMC probe failed %d\n", ret);
741 static struct platform_driver aspeed_smc_driver = {
742 .probe = aspeed_smc_probe,
743 .remove = aspeed_smc_remove,
746 .of_match_table = aspeed_smc_matches,
750 module_platform_driver(aspeed_smc_driver);
752 MODULE_DESCRIPTION("ASPEED Static Memory Controller Driver");
753 MODULE_AUTHOR("Cedric Le Goater <clg@kaod.org>");
754 MODULE_LICENSE("GPL v2");